232
Appendix D
The center offers publications and maintains a consulting staff and publishes
a Reliability Journal [4.19] and a 1000 page report [4.18] in NPRD 95 "Non
Electronic Parts Reliability Data" which gathers data from several sources.
In this appendix excerpts from [4.17] Tables D.6 and D.7 are presented as
well as a reliability Section II from [4.21] published with permission.
The reference [4.30] offers failure rates for the marine industry and
these are in Table 4.1.
When the failure rates are selected the environment is important. The
second item is the number of items and hours to develop the failure.
One item is how long a system can be expected to operate. Table D.1 is
a good guide from bearing life estimates. It should be noted bearing life
and MTTF need not be the same. So that
R(t) : -’~t
(D. 1)
set R(t) to say, 0.90 for life 100,000 hr Table D.1 and solve for the 2 and
MTTF. The number may or may not be possible for the physical system.
The following Sections II and III are published with permission of the
McGraw-Hill companies from Mechanical Design and Systems Handbook,
Harold A. RothBart, Editor, McGraw-Hill, Inc., 1964. The chapter cited
is 18.11 System Reliability Analysis by Carl H. Levinson. The source
for Section II is "Generic Failure Rates," Martin Company Report,
Baltimore, Md.
Table D.1 Bearing-life recommendations for various classes of machinery
Type of application
Life, kh
Instruments and apparatus for infrequent use
Up to 0.5
Aircraft engines
0.5-2
Machines for short or intermittent operations where service
4-8
interruption is of minor importance
Machines for intermittent service where reliable operation is
8-14
of great importance
Machines for 8-hr service which are not always fully utilized
14-20
Machines for 8-hr service which are fully utilized
20-30
Machines for continuous 24-hr service
50-60
Machines for continuous 24-hr service where reliability is of
100-200
extreme importance
Reproduction with permission of the McGraw-Hill companies from J. Shigley and C.R.
Mischke, Mechanical Engineering Design, 5th Edition 1989.
Appendix D
The center offers publications and maintains a consulting staff and publishes
a Reliability Journal [4.19] and a 1000 page report [4.18] in NPRD 95 "Non
Electronic Parts Reliability Data" which gathers data from several sources.
In this appendix excerpts from [4.17] Tables D.6 and D.7 are presented as
well as a reliability Section II from [4.21] published with permission.
The reference [4.30] offers failure rates for the marine industry and
these are in Table 4.1.
When the failure rates are selected the environment is important. The
second item is the number of items and hours to develop the failure.
One item is how long a system can be expected to operate. Table D.1 is
a good guide from bearing life estimates. It should be noted bearing life
and MTTF need not be the same. So that
R(t) : -’~t
(D. 1)
set R(t) to say, 0.90 for life 100,000 hr Table D.1 and solve for the 2 and
MTTF. The number may or may not be possible for the physical system.
The following Sections II and III are published with permission of the
McGraw-Hill companies from Mechanical Design and Systems Handbook,
Harold A. RothBart, Editor, McGraw-Hill, Inc., 1964. The chapter cited
is 18.11 System Reliability Analysis by Carl H. Levinson. The source
for Section II is "Generic Failure Rates," Martin Company Report,
Baltimore, Md.
Table D.1 Bearing-life recommendations for various classes of machinery
Type of application
Life, kh
Instruments and apparatus for infrequent use
Up to 0.5
Aircraft engines
0.5-2
Machines for short or intermittent operations where service
4-8
interruption is of minor importance
Machines for intermittent service where reliable operation is
8-14
of great importance
Machines for 8-hr service which are not always fully utilized
14-20
Machines for 8-hr service which are fully utilized
20-30
Machines for continuous 24-hr service
50-60
Machines for continuous 24-hr service where reliability is of
100-200
extreme importance
Reproduction with permission of the McGraw-Hill companies from J. Shigley and C.R.
Mischke, Mechanical Engineering Design, 5th Edition 1989.